Engine packing



April 25, 1939. R c. PAYNE ENGINE PACKING Original Filed July 16, 1934Patented Apr. 25, 1939 UNITED STATES ATENT OFFICE ENGINE PACKING RufusC. Payne, Chicago, Ill.

Claims.

In a reciprocating engine, compressor or the like, the usual form ofpiston fits into the cylinder with a small amount of clearance, and hasthereon certain circumferential grooves. Seated 5 in these grooves arethe conventional elements which we term piston rings, said rings beingtransversely out having more or less inherent resiliency to stop thepassage of gas, thereby conserving compression, and thus more power ismade available. These rings must quite accurately fit the contour of thecylinder walls as well as the side walls of the circumferential grooves.In new pistons this is more or less simple. But after a certain amountof use the cylinders become worn out of round by the unequal pressureexerted by the reciprocating piston, due mostly to the side thrust ofthe connecting rod. Under these conditions the parts become worn, and wehave What is termed piston slap and loss of compression. A ring toconform to the out of round cylinder must have incorporated in itsmakeup a quality of resiliency. By seating underneath the ring in thering groove a thin spring, termed an expander or inner spring, thisdifiiculty is overcome, since the expander supplements the naturalthrust of the ring, thus causing it to conform to the out of roundcylinder. The unequal side thrust of the piston occurring in certainpredetermined directions causes unequal wear on the piston. In order tocompensate for this Wear,

I have cam ground or reduced the thickness of my ring in diametricallyopposite points to allow the intermediate portions of the ring to bethrust outwardly by my expander to take the place of such wear, thisarrangement also reducing the piston slap. In addition to the passage ofgas past the ring during the operation of the engine, oil from thelubricating system passes into the combustion space where it producessmoke, deposits carbon, etc., and is thus a nuisance and an addedexpense. Various efforts have been made to return this oil to the crankcase after lubricating the cylinder walls.

It is the object of this invention to produce a 45 one piececircumferentially slotted ring that shall to the utmost extent possible,correct the unfavorable conditions found in a worn cylinder in which theengine loses compression and is pumping oil. By pumping oil is meantlubricating oil is pumped into the combustion chamber and partiallyburned.

These objects and others will appear as I proceed with the descriptionwherein reference is made to the accompanying drawing, where like n e as ef to l P s n t e d fierent views. It is to be understood that theillustrative drawing used is for the purpose of showing the preferredform of my invention, and that I do not wish the interpretation of myinvention to be limited to these exact details, but shall include allmodifications embraced in the intent and purpose of my invention asdisclosed in my specifications, and as further defined in the claims.

The structure described is illustrated by the accompanyingdrawing inwhich Fig. 1 is a horizontal section through a piston, showing theinvention in position thereon.

Fig. 2 is a section on line 2-2 of Fig. 3.

Fig. 3 is a vertical section through a cylinder and a piston, with partsbroken away showing the invention in position thereon.

Fig. 4 is an enlarged section of the oil ring, piston and cylinder withparts broken away.

Fig. 5 is an enlarged section of the compression ring, cyinder andpiston with parts broken away.

Fig. 6 is an enlarged sectional view of my ring taken on a median line,showing the solid sections of said ring.

Numeral l indicates a piston of the conventionalv sort, 2 thecircumferential grooves for holding the rings, 3 my one piececircumferentially slotted oil ring having the slot 4 midway of the bodyand continuing around to within a short space of the transverse cut asat 5, and terminating diametrically opposite this cut as at 6. Theserings are seated in the slots 2 of the piston l in the usual manner.

The circumferential slot 4 divides the ring into, what may be termed, anupper and a lower section. These sections are connected together only,at their ends and at their central portions. The ring 3 is provided witha circumferential groove, part of which is in one section and part inthe other, Figsr i and 5. The sides of the roove, being curved incross-section, constitute cam surfaces which are adapted to be engagedby a sinuous expander ring 9.

By thus slotting the ring circumferentially we are enabled through theaction of my expander I to not only give the ring an outward or radialthrust, but at the same time a thrust of each piece sideways by reasonof the fact that the edges 8 of expander I tend to travel along thecurved surface 9. This outward thrust is continued around to the twooppositesidesofthering up to the solid portions 5 and 6, which arepoints where pivotal action of the piston takes place, and along theline of the piston pin (not shown). As the portions 5 and 6 of my ringare thinner than the major or intermediate portions, they are weaker andare flexed at these points, while the intermediate portions l0 and l lare caused to be pushed outwardly against the cylinder walls where themain amount of wear occurs. This action is brought about largely by thehumps in my expander and the manner in which they are disposed.

As shown in Fig. 1 there are more complete humps of the expanderengaging the piston on each side of the median line I2 as at H) or IIWhere the greatest pressure is required than there are on either side ofthe median line l3. These humps are equally distributed about eachmedian line. So in Fig. 2 as shown, I may vary the number of humps inthe expander but keeping a similar relation to the flexing points of myring and the teetering points of the piston.

In installing rings in a cylinder it is quite necessary that in wearingthem in or getting a permanent seat, the ring be prevented from turningin its groove in the piston. To take care of this I insert a pin intheexpander as at [4; this in turn may enter a hole in the piston by aloose fit. This pin is located on the pivoting line of the cylinder anddiametrically opposite the transverse cut in said ring. By takingadvantage of the cam formation (gradual reduction of the depth) of myring, I create a condition so that one or more of the humps on myexpander which are located in the gradually decreasing thickness of saidring tend permanently to locate themselves therein. If I construct myexpander such that two humps come within the limits of the reducedthickness, they are placed symmetrical with respect to such reducedportion, as at l5, Fig. 1, and any tendency to rotate circumferentiallyin either direction would be the equivalent of climbing a hill, thus thepoint of least resistance is to remain symmetrical relative to a lineevenly dividing the limits of such reduced portion, or cam groundsection. -As the expander is pinned to the piston and the humps on theexpander are located in thevalley between two elevated portions, itfollows that the ring is prevented from rotating circumferentially.

In reducing the depth of my ring I preferably make the reductiongradual, say like a cam, commencing about 45 as at I6, from amedian'line and continuing the reduction to the median line as at H, andfrom this gradually increasing for another 45 as at 18, where the normaldepth is reached. This process is repeated on the opposite side as atI9, 20, 2! and I have a cam formation at diametrically opposite pointson my ring. By this method I get a smooth even resiliency.

The bearing face of one of the rings is adapted to be formed to preventpassage of oil.

As shown in Fig. 4, this is accomplished by bevelling the upper outercorners of the two sections of the ring as at 22, respectively. Thisconstruction will permit the ring to override the oil, on the upwardstroke, while on the downward stroke the sharp corner 24 will scrape theoil from the cylinder wall and cause it to flow back to the crank casethrough the passages 25 drilled in a slanting direction through thepiston I. 'These passages are spaced from each other around theperiphery of the piston and at the very edge of the oil ring groove. Bymeans of this slot 4 along the middle line of the ring I form anotherscraping edge 26 on the lower corner of the upper section, whereby I getthe effect of two rings in one. The oil from this source scraped fromthe cylinder wall passes inwardly through said slot 4 and around theedges'of my expander as at 21, thence back to the crank case throughopenings 28, provided in the piston wall. I am able through the meansjust described to keep up a continual circulation of fresh lubricatingoil around my expander thereby keeping it in a cool and live condition.Unless provision is made for circulating the oil, the same will becomeoverheated and disintegrated by the heat of combustion in the cylinders.As a result a gummy substance as a residue is formed, and soon the sidesof the rings will become glued to the walls of the circumferential slotsthereby impeding their free movement. Freedom of movement is necessaryfor the perfect performance of any piston ring as otherwise they willbecome overheated and lose their resiliency. This condition appliesequally well to the expander because if this element is not relieved ofthe excessive heat as it accumulates, it loses its elasticity, therebydepriving the ring of the necessary resiliency for it to assume the outof round of a worn. cylinder.

By varying the contour of the bearing face of my ring, I am able to useit as a compression, or, I might term it, a compensator ring. When usedfor this purpose a portion of the bearing face of the ring is providedwith a slight inward circumferential curve as at 29. The desirablefeature of this contour is such that as the narrow faces 39 and 3| weardown from use the contact surface increases as the wear continues.

It is not necessary to repeat the explanation of the action of theexpander between the inside of the ring and the bottom of the groove, asthe slot on the median line and curve on the inner surface is the sameas my oil ring just described. This ring stops any gas that may get pastthe fire ring 32.

What I claim and wish to secure by Letters Patent is:

1. A split piston ring having a pair of circumferential slots extendingthrough the ring at each side of the diameter passing through the splitin the piston ring and extending on opposite sides from points adjacentto the split to points adjacent to the portion of the ring diametricallyopposite said split, said ring tapering from points angularly spacedfrom the ends thereof toward the diameter passing through said split andhaving a circumferential groove provided with inclined side walls forreceiving a light sinuous spring.

2. A split piston ring having a circumferential slot therethrough ateach side of the split and extending around the ring a distance slightlyless than the semi-circumference of the ring, said ring having acircumferential groove on its periphery, said groove being curved incross-section, said ring gradually increasing in thickness from the endsto points 90 spaced therefrom and then gradually decreasing in diameterto a point diametrically opposite said ends.

3. A split piston ring for a circumferential groove on a piston for anengine, said ring having two circumferential slots extending radiallytherethrough, said slots extending from points adjacent the ends of saidring to points opposite said ends on said ring for dividing said ringinto two sections, the inner peripheral surface of said ring beingconcave, a sinuous spring member engaging the concave surface of saidring for radially expanding said ring and for spreading the ringsectionsapart, and means for preventing rotation of said spring member, saidring being of varying thickness to provide two portions only of maximumthickness arranged opposite each other at substantially 90 from the endsof said ring, said thickened portions gradually tapering into twothinner portions arranged opposite each other.

4. In combination, a piston having a circumferential groove therein, asplit piston ring therein, said ring being thinner at two diametricallyopposite sides only than at the remaining portion thereof, a sinuousring spring element between the bottom of said groove and said ring andengaging said ring, the curves of said element being symmetricallyarranged at each side of a diameter passing through the thin portions ofsaid ring, and means for preventing circumferential movement of saidelement.

5. In combination, a cylinder, a piston for said cylinder, said pistonhaving a circumferenthe ring to points opposite said split to provide 5spaced ring sections, the upper edges of the ring sections each beingbeveled, the inner peripheral surface of said ring being concave, and asinuous resilient ring interposed between the concave surface of saidring and the piston Wall for radially 10 expanding said ring and forspreading said sections, said ring being of varying thickness to providetwo thin portions arranged 180 apart and only two portions of maximumthickness also arranged 180 apart and 90 from the split in said 15 ring.

RUFUS C. PAYNE.

